Process for the production of lactams

Abstract

A one-step method for the reductive amination of a heterocyclic to produce a nitrogen-containing heterocyclic. The feedstock is contacted with a mixed metal catalyst in which the metal comprises palladium and one of ruthenium, rhodium or rhenium.

I claim: 
     
       1. A process for producing a lactam comprising contacting a feedstock selected from the group consisting of acid anhydrides, dicarboxylic acids, lactones, and imides, said feedstock having 4 to 6 carbon atoms in the backbone with a catalyst system comprising palladium and at least one second metal selected from the group consisting of ruthenium, rhodium and rhenium under conditions to convert at least a portion of the feedstock to the lactam. 
     
     
       2. A process for producing a lactam comprising contacting a feedstock selected from the group consisting of acid anhydrides, dicarboxylic acids, lactones, and imides, said feedstock having 4 to 6 carbon atoms in the backbone, hydrogen, and an aminating agent, with a catalyst system comprising palladium and at least one second metal selected from the group consisting of ruthenium, rhodium and rhenium in a polar liquid medium under conditions to convert at least a portion of the feedstock to the lactam. 
     
     
       3. A process as in claim 2 wherein the feedstock is selected from acid anhydrides and their corresponding acids. 
     
     
       4. A process in accordance with claim 2 wherein said second metal of said catalyst consists essentially of ruthenium. 
     
     
       5. A process in accordance with claim 2 wherein said catalyst further comprises a particulate support selected from the group consisting of alumina, silica-alumina, silica, zirconia and carbon and in which the palladium and the ruthenium are deposited on the particulate support. 
     
     
       6. A process in accordance with claim 5 wherein said catalyst consists essentially of ruthenium and palladium on a particulate alumina support. 
     
     
       7. A process in accordance with claim 6 where the ruthenium weight fraction of the catalyst, defined as wt. Ru/wt. (Ru+Pd), is in the range of from about 0.1 to 0.9. 
     
     
       8. A process in accordance with claim 6 wherein said ruthenium weight fraction is in the range of from about 0.3 to about 0.8. 
     
     
       9. A process in accordance with claim 6 wherein said ruthenium weight fraction is in the range of from about 0.4 to about 0.7. 
     
     
       10. A process in accordance with claim 9 wherein the feedstock is selected from the group consisting of maleic anhydride, maleic acid, succinic anhydride or succinic acid. 
     
     
       11. A process in accordance with claim 10 wherein said aminating agent comprises ammonia. 
     
     
       12. A process in accordance with claim 11 wherein said polar liquid medium is selected from the group consisting of water and ethers. 
     
     
       13. A process in accordance with claim 12 wherein said polar liquid medium is predominantly water. 
     
     
       14. A process in accordance with claim 13 wherein each mole of feedstock is brought together with from about 1 to about 5 moles of ammonia and 3 to about 25 moles of water, and with about 0.01 to about 0.75 grams of mixed palladium and ruthenium contained in said catalyst. 
     
     
       15. A process in accordance with claim 14 wherein the feedstock comprises maleic anhydride or maleic acid and each mole of feedstock is brought together with from about 1.2 to about 2 moles of ammonia and about 12 to about 15 moles of water, and with about 0.2 to about 0.6 grams of mixed palladium and ruthenium contained in said catalyst. 
     
     
       16. A process in accordance with claim 15 further comprising maintaining the temperature in the range of from about 200° to about 300° C. 
     
     
       17. A process in accordance with claim 16 further comprising maintaining the temperature in the range of from about 240° to about 270° C. 
     
     
       18. A method in accordance with claim 16 further comprising maintaining the pressure in the range from about 500 to about 5000 psig by hydrogen addition. 
     
     
       19. A method in accordance with claim 17 further comprising maintaining the pressure in the range of from about 1500 to about 4000 psig by hydrogen addition.